|
80 |
Tutorial.
Julie
Morris. Medical statistics |
|
81 |
EMQ.
Phenylketonuria |
|
82 |
EMQ.
Headache |
Abbreviations.
PA: phenylalanine.
PAH: phenylalanine hydroxylase.
PAHD: phenylalanine hydroxylase deficiency.
PKU: phenylketonuria.
Tyr: tyrosine.
Option list.
|
A. |
autosomal dominant |
|
B. |
autosomal recessive |
|
C. |
X-linked dominant |
|
D. |
X-linked recessive |
|
E. |
1 in 100,000 |
|
F. |
1 in 50,000 |
|
G. |
1 in 10,000 |
|
H. |
1 in 5,000 |
|
I. |
deficiency in phenylalanine hydroxylase |
|
J. |
deficiency in phenylalanine oxidase |
|
K. |
deficiency in phenylalanine transferase |
|
L. |
deficiency in phenylketone hydroxylase |
|
M. |
deficiency in phenylketone oxidase |
|
N. |
raised PA levels |
|
O. |
reduced PA levels |
|
P. |
raised tyrosine levels |
|
Q. |
reduced tyrosine levels |
|
R. |
normal tyrosine levels |
|
S. |
No |
|
T. |
Yes |
|
U. |
unknown |
What
is PKU? Write your answer – there is no option list.
Question
2.
What is PKU due to? Use the option list.
Question
3.
What levels of PA and Tyr are typical in PKU? Use the
option list. This is not a real EMQ as there are two answers.
Question
4.
Is PKU subdivided into different categories? If “yes”,
what are the categories? Write your answer – there is no option list.
Question
5.
Which, if any, of the following statements is true about hyperphenylalaninaemia?
This is not a true EMQ as more than one answer may be correct.
Option List
|
A.
|
it blocks
growth hormone |
|
B.
|
it destroys
astrocyte miosis |
|
C.
|
it disrupts
folic acid activity |
|
D.
|
it enhances
vitamin A activity |
|
E.
|
it interferes with myelin synthesis |
|
F.
|
it negates the
effects of vitamin C |
|
G.
|
nobody knows,
nobody cares; especially me |
Question
6.
How is PKU inherited? Use the option list.
Question
7.
Which chromosome houses the gene related to PKU
transmission?
Question
8.
How many mutations of the gene related to PKU have so far
been identified?
Question
9.
Is a person with PKU likely to have one or two mutations
of the relevant gene?
What
is BH4?
Question 11.
What
is pegvaliase?
Question 12.
What
is the approximate prevalence of PKU in Caucasians?
Question 13.
What
is the approximate prevalence of PKU carrier status in Caucasians?
Question 14.
The
prevalence of PKU varies between ethnic groups.
Match each of the following ethnic groups to the closest
prevalence given in the option list.
Option List
|
H.
|
1 in 1,000 |
|
I.
|
1 in 2,500 |
|
J.
|
1 in 5,000 |
|
K.
|
1 in 10,000 |
|
L.
|
1 in 100,000 |
|
M.
|
1 in 150,000 |
|
N.
|
1 in 200,000 |
|
O.
|
1 in 1,000,000 |
|
Ethnic group |
Prevalence |
|
Turkish |
1 in 2,600 |
|
Irish |
1 in 4,500 |
|
Caucasian |
1 in 10,000 |
|
East Asian |
1 in 10,000 |
|
Japanese |
1 in 143,000 |
|
Finnish |
1 in 200,000 |
Question
15.
Which, if any, of the following are characteristic of
PKU?
Option list.
|
A. |
alopecia |
|
B. |
angst |
|
C. |
facial dysmorphism |
|
D. |
facial hair in females and pre-pubertal males |
|
E. |
kyphosis |
|
F. |
macroorchidism in post-pubertal males |
Question
16.
Are fetal PKU levels higher or lower than maternal? There
is no option list.
Question
17.
Which, if any, of the following are true in relation to the maternal
phenylketonuria syndrome? This is not a true EMQ as there may be more than correct
answer.
Option
list.
|
A. |
asymptomatic bacteruria is more common |
|
B. |
cholestasis of pregnancy is more common |
|
C. |
early onset gestational hypertension is more common |
|
D. |
eczema is more common |
|
E. |
gallstones are more common |
|
F. |
miscarriage is more common |
|
G. |
MPKUS is usually due to non-adherence to a low
phenylalanine diet |
|
H. |
porphyria is more common |
|
I. |
reversible posterior cerebral syndrome is more common |
|
J. |
urinary tract urea stones are more common |
|
K. |
none of the above |
Question
18.
What are the main consequences for the offspring of
untreated PKU in the mother?
Question
19.
Is screening for PKU a routine part of the neonatal
screen in the UK?
Question
20.
The test for PKU used to be known by the name of its
inventor. Who was he and why did he have a particular interest? There is no option list and no one is
going to ask you except me!
What
conditions are included in the routine neonatal ‘heelprick’ screening test? There
is no option list.
Question 22.
Is
neonatal screening for PKU still done using Guthrie’s bacterial inhibition
method? If not, what method is used? There is no option list.
Question 23.
What
is the main treatment of PKU and what problems are associated with it? There is
no option list.
Question 24.
How
long should the main treatment of PKU be continued and why? There is no option
list.
Question
25.
Lead-in
A woman with PKU is planning her first pregnancy at the
age of 22. She has been off the PKU-restricted diet since the age of 10 and can
barely remember being on it. Should she be advised to re-start the diet? If
‘yes’, when should she start and what explanation would you give for the
advice?
Question
26.
Lead-in
Which if any of the following statements are true about screening
for PKU and its effects in the neonate born to a woman with PKU ?
Option
list.
|
A. |
routine bloodspot screening alone is required |
|
B. |
the neonate should be examined by a paediatrician for
signs of PKU |
|
C. |
the baby should have developmental assessment, even if
it does not have PKU |
|
D. |
an ultrasound scan should be done because of the
increased risk of developmental dysplasia of the hip |
|
E. |
the baby should be started on a low PA diet until all
assessments are complete |
|
F. |
none of the above. |
Question
27.
Lead-in
Is breast-feeding advisable for women with PKU?
Question
28.
Lead-in
Are any other therapeutic approaches available? If ‘yes’,
what are they and how do they work? If ‘yes’ use the option list for the mode
of action.
Option List
|
A.
|
it binds PA to circulating plasma proteins, reducing
its free levels |
|
B.
|
it increases
hepatic metabolism of PAH. |
|
C.
|
it increases
renal excretion of PA |
|
D.
|
it is a
co-factor for PAH, increasing its efficacy in reducing PA levels |
|
E.
|
it is phenylalanine
ammonia lyase, capable of breaking down PA |
|
F.
|
it is a
synthetic PAH enzyme |
|
G.
|
it reduces
absorption of PA from the small bowel |
TOG CPD questions. These are open-access, so reproduced here.
Regarding phenylketonuria
(PKU):
1. it is a deficiency of the amino acid
phenylalanine (Phe). True False
2. it is an X-linked recessive inherited
metabolic disease. True False
3. it results in a deficiency in the amino
acid tyrosine. True False
4. it is treated with a low-phenylalanine
restricted diet. True False
5. the incidence is approximately 1:1000. True False
6. the Newborn Screening Programme has been a
great success in the diagnosis and management of children with PKU. True False
7. neonates with fetal alcohol syndrome and
PKU are clinically difficult to distinguish at birth. True False
8. in utero exposure to very high levels of
phenylalanine results in reversible neurological damage to the fetus. True False
9. pregnancy outcome is improved
substantially when treatment results in low maternal phenylalanine
concentrations ideally before conception. True False
10. oral methods of contraception should be
switched to barrier methods at least 12 months before conception. True False
11. the risk of congenital heart defects is
estimated to be 7–10%. True False
12. it is an indication for early delivery by caesarean
section. True False
13. neonates born to mothers with PKU should be
offered screening for PKU as per the routine national screening programme. True False
14. breastfeeding is contraindicated in women
with PKU. True False
With regard to the biochemistry of PKU:
15. Phe is passively transported across the
placenta. True False
16. fetal Phe levels are approximately 1.25-2.5
times > than maternal levels. True False
Children born to women with
PKU:
17. tend to have blue eyes. True False
18. are fair skinned. True False
With regard to the effect of high Phe levels on loss of IQ or
behavioural changes:
19. these changes are reversible in utero. True False
20. they are reversible with resumption of diet
deficient of Phe. True False
83. EMQ.
Headache.
1. abdominal migraine
2. analgesia overuse, aka
medication overuse
3. bacterial meningitis
4. benign intracranial
hypertension
5. BP check
6. cerebral venous sinus
thrombosis
7. chest X-ray
8. cluster
9. severe PET / impending
eclampsia
10. malaria
11. meningococcal meningitis
12. methyldopa
13. methysergide
14. migraine
15. MRI brain scan
16. nifedipine
17. nitrofurantoin
18. pancreatitis
19. sinusitis
20. subdural haematoma
21. subarachnoid haemorrhage
22. tension
23. ultrasound scan of the
abdomen
Scenario 1.
A 40-year-old para 3 is
admitted at 38 weeks by ambulance with severe headache of sudden onset. She describes it as “the worst I’ve ever
had”. Which diagnosis needs to be excluded urgently?
Scenario 2.
A 32-year-old para 1 has
recently experienced headaches.
They are worse on exercise, even mild exercise such as walking up stairs. She
experiences photophobia with the headaches.
Which is the most likely diagnosis?
Scenario 3.
A woman returns from a
sub-Saharan area of Africa. She develops severe headache, fever and rigors. What diagnosis should particularly be
in the minds of the attending doctors?
Scenario 4.
A woman at 37 weeks has s. They
particularly occur at night without obvious triggers. They occur every few days.
Scenario 5.
A primigravida has had s on a regular basis
for many years. They occur most days, are bilateral and are worse when she is stressed.
What is the most likely diagnosis?
Scenario 6.
A woman complains of
recent headaches at
36 weeks. The history reveals that they started soon after she began treatment
with a drug prescribed by her GP. Which is the most likely of the following
drugs to be the culprit: methyldopa, methysergide, nifedipine or nitrofurantoin?
Scenario 7
A woman is booked for
Caesarean section and wishes regional anaesthesia. She had severe headache due
to dural tap after a previous Caesarean section. She wants to take all possible
steps to reduce the risk of having this again. Which of epidural / spinal
anaesthesia has the lower risk of causing dural tap?
Scenario 8
A 25-year-old primigravida
attends for her 20-week scan and complains of headache which started two weeks
before. There is no significant history. The pain occurs behind her right eye
and she describes it as severe and “stabbing” in nature. The pain is so severe
that she cannot sit still and has to walk about. She has noticed that her right
eye becomes reddened and “watery” during the attack and her nose is “runny”.
The attacks have no obvious trigger and mostly occur a few hours after she has
gone to sleep. The usually last about 20 minutes. She has no other symptoms. She
smokes 20 cigarettes a day but does not take any other drugs, legal or
otherwise. What is the most likely diagnosis?
Scenario 9
A woman has a 5-year
history of unilateral, throbbing headache often preceded by nausea, visual
disturbances, photophobia and sensitivity to loud noise. What is the most
likely diagnosis?
Scenario 10
A primigravida is admitted at 38 weeks
complaining of headache, abdominal pain and a sensation of flashing lights. What
would be the appropriate initial investigation?
Scenario 11
A woman with BMI of 35 attends for her
combined Downs syndrome screening test. She complains of pain behind her eyes.
The pain is worst last thing at night before she goes to sleep or if she has to
get up in the night. She has noticed she has noticed horizontal diplopia on several
occasions. She has no other symptoms. Examination shows papilloedema.
Scenario 12
A grande multip of 40 years
experienced sudden-onset, severe headache, vomited several times and then
collapsed, all within the space of 30 minutes. She is admitted urgently in a
semi-comatose state. Examination shows neck-stiffness and left hemi-paresis.
Scenario 13.
What did the MMR include
as “red flags” for headache in
pregnancy? These are not on the option list – you need to dig them out of your
head.
This
is not an EMQ. It relates to the incidence of various conditions in women who
have migraine. Choose the appropriate arrow for each.
Option list.
|
A |
asthma |
↔ |
↑ |
↓ |
|
B |
developmental
dysplasia of the hip in child |
↔ |
↑ |
↓ |
|
C |
diabetes |
↔ |
↑ |
↓ |
|
D |
Down’s
syndrome in child |
↔ |
↑ |
↓ |
|
E |
hypertension |
↔ |
↑ |
↓ |
|
F |
ischaemic
heart disease |
↔ |
↑ |
↓ |
|
G |
PET |
↔ |
↑ |
↓ |
|
H |
stroke |
↔ |
↑ |
↓ |
Scenario 15.
Which
of the following drugs is contraindicated in the prophylaxis of migraine in pregnancy?
Option list.
|
A |
amitriptyline
|
|
B |
ß-blockers |
|
C |
ergotamine |
|
D |
low-dose
aspirin |
|
E |
pizotifen |
|
F |
pregabalin |
|
G |
tricyclic
antidepressants |
|
H |
verapamil |
Scenario 16.
Which,
if any, of the following statements is true about posterior reversible
encephalopathy syndrome. This is not a true EMQ as there may be > 1 true
answer.
Option list.
|
A |
‘thunderclap’
headache is typical |
|
B |
‘handclap’
headache is typical |
|
C |
classically
occurs in the early puerperium and is recurrent |
|
D |
classically
occurs in the early puerperium and is not recurrent |
|
E |
arterial
beading is typically seen on MRI |
|
F |
arterial
beating is typically seen on MRI |
|
G |
arterial
bleeding is typically seen on MRI |
|
H |
venous
beading is typically seen on MRI |
|
I |
venous
beating is typically seen on MRI |
|
J |
venous
bleeding is typically seen on MRI |
|
K |
diagnosis
requires lumbar puncture and evidence of ↑ CSF pressure |
|
L |
treatment
is with nimodipine |
Scenario 17.
Which,
if any, of the following statements is true about reversible cerebral
vasoconstriction syndrome. This is not a true EMQ as there may be > 1 true
answer.
Option list.
|
A |
‘thunderclap’
headache is typical |
|
B |
‘handclap’
headache is typical |
|
C |
classically
occurs in the early puerperium and is recurrent |
|
D |
classically
occurs in the early puerperium and is not recurrent |
|
E |
arterial
beading is typically seen on MRI |
|
F |
arterial
beating is typically seen on MRI |
|
G |
arterial
bleeding is typically seen on MRI |
|
H |
venous
beading is typically seen on MRI |
|
I |
venous
beating is typically seen on MRI |
|
J |
venous
bleeding is typically seen on MRI |
|
K |
diagnosis
requires lumbar puncture and evidence of ↑ CSF pressure |
|
L |
treatment
is with nimodipine |
Questions from TOG article
by Revell & Moorish. 2014. These are open
access.
You can find the questions here.
Headaches in pregnancy
Red flag features for headaches include:
1. headache that changes with posture True / False
2. associated vomiting True / False
3. occipital location True / False
4. associated visual disturbance. True / False
Migraine is classically,
5. bilateral. True / False
6. pulsating. True / False
7. aggravated by physical exercise. True / False
With regard to migraine headaches in pregnancy,
8. there is an increase in the frequency of
attacks without aura. True / False
9. women who suffer from this have not been
shown to have an increase in the risk of pre-eclampsia. True / False
10. the 5HT1-receptor sumatriptan has been shown to
be teratogenic. True / False
11. women presenting with an aura for the first
time are not at an increased risk of intracranial disease. True / False
Posterior
reversible encephalopathy syndrome,
12. is associated with an impairment of the
autoregulatory mechanism which maintains constant cerebral blood flow where
there are blood pressure fluctuations. True / False
13. when it is associated with pre-eclampsia,
management should follow the pathway for managing severe pre-eclampsia. True / False
With regard to cerebral venous thrombosis,
14. the incidence in western countries in pregnancy
ranges from 1 in 2500 deliveries to 1 in 10 000 deliveries. True / False
15. the greatest risk in pregnancy is mainly in
the last four weeks. True / False
16. the most common site is the sagittal sinus. True / False
17. a plain computed tomography is a highly sensitive
investigation. True / False
18. T2-weighted magnetic resonance imaging has been
shown to have limited value in diagnosis. True / False
19. the outcome is better when it is associated
with pregnancy and the puerperium compared to that occurring outside pregnancy. True / False
20. when it occurs in pregnancy, it is a
contraindication for future pregnancies. True / False
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